US Weekly reports that Holmes made secret calls to Kidman in the lead-up to the divorce, with a source saying: "Nicole has been supportive, saying she's been through it too and to hang in there."

The source added: "She has been a private friend not many people know about."

The tabloid claims that Holmes reached out to Kidman after mounting fears about her daughter Suri, and speculates that they may have communicated on the disposable phone Holmes was rumored to have used to avoid detection.